Oh and Jack chains can be traced back way before 1407, they even have them in the Bohemian mansctiots at the beginning of the game. Again, trade was great in Europe. If France had it, so did German states, if Germans States had it, so did eastern European kingdoms. And hey, 2000 km is absolutely no distance at all. People were able to travel these distances. Need I remind you of the crusades? The same logistics apply to any army or merchant.
Edit: 1000 km *